Ultracompact laser projection systems based on two-dimensional resonant microscanning mirrors

Recently, there has been substantial progress in the development of ultracompact image projection systems. This has been enabled by the availability of electrically modulated laser sources for all three elementary colors and a 2D resonant microscanning mirror as a micro-opto-electro-mechanical system (MOEMS) device for light deflection. The laser beam formed by collimator optics is directed onto the micro-scanning mirror. Given the movement of the mirror, the laser beam scans the entire image area. By driving the mirror and electrically modulating the intensity of the laser beam in a synchronous manner, a projection of images can be achieved. In this contribution, we present the theoretical background of the projection system as well as the latest achievements in system design. Both monochrome and full-color systems are currently available. The latter uses a separate laser bank as an RGB light source, which is coupled with a projection head. For monochrome red systems, the laser diode can be integrated into the projection head as well, whose volume can be reduced to 15×7×5 mm. All systems have video graphics array (VGA) (640×480 pixels) resolution and operate with 8-bit color depth per pixel and 50 frames per second.